Creating a random number for a local storage keyName

Question

I am trying to create a random number as the keyName for a local storage for example in this code: localStorage.setItem('_8bcsk999r778311o', input.value); I want to create a random number in the place of "_8bcsk999r778311o" using javascript . Is it possible , and if possible , could you please send me the code? Thanks in advance!

Did you try to find anything on the web? If you had you would get thousands of results. Asking here should be your last resort in getting ab answer to your question, you should first search for your answer since there is a chance a similar question was asked by someone before you and it got answers. — Archit Gargi, Jun 12 '22 at 06:33
KrotAsch, so the main task here is to generate a random number. The localStorage part is secondary or even irrelevant. Did you try searching for how to generate a random number in Javascript? One simple google search for "Generate a random number in Javascript" would yield thousands of results. What did you try? — Loner, Jun 12 '22 at 06:35
Do you want a random number or a unique number? These are not the same and have different solutions. — Yogi, Jun 12 '22 at 06:59
How do you intend to deal with numerical conflicts? What sort of range of numbers are permissable? Why numbers and not strings where it is easier to generate unique strings? How many numeric keys do you expect? — Professor Abronsius, Jun 12 '22 at 07:07

Behnam Asaei · Answer 1 · 2022-06-12T06:42:58.320

1

Takes a number from 1 to 10 and save into number then with floor convert number to integer

//random integer from 0 to 10000:
let number = Math.floor(Math.random() * 10000);
localStorage.setItem(number, input.value);

In JavaScript, floor() is a function that is used to return the largest integer value that is less than or equal to a number. see more

Math.random() returns a random number between 0 (inclusive), and 1 (exclusive): see more

edited Jun 12 '22 at 06:42

answered Jun 12 '22 at 06:31

Behnam Asaei

89
4

Pls add some supporting information and documentation so that others can understand your code. – Archit Gargi Jun 12 '22 at 06:34

score 1 · Accepted Answer · answered Jun 12 '22 at 07:30

1

const random_id = `_${Math.random().toString(30).substr(2,17) + Math.random().toString(30).substring(2,17)}`
console.log(random_id)

//localStorage.setItem(random_id, 'value goes here');

Very simple and fast solution

answered Jun 12 '22 at 07:30

Muhammad Atif Akram

1,204
1
4
12

score 0 · Answer 3 · answered Jun 12 '22 at 06:38

var key = "";
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

for (var i = 0; i < Math.floor(10+10*Math.random()); i++) {
    key += possible.charAt(Math.floor(Math.random() * possible.length));
}
localStorage.setItem(key, input.value);

I hope this will be helpful for you. Thanks.

score 0 · Answer 4 · answered Jun 12 '22 at 07:31

You could utilise the random nature of the window.crypto object to deliver your numeric / string IDs with a simple function as below. By tweaking the input arguments you can easily generate either numeric or alphanumeric strings of varying sizes.

Uint32Array

crypto.getRandomValues()

const uniqid = (length = 2, base = 16) => {
  let t = [];
  // invoke the crypto
  let crypto = window.crypto || window.msCrypto;
  // create a large storage array
  let tmp = new Uint32Array(length);
  // populate random values into tmp array
  crypto.getRandomValues( tmp );
  
  // process these random values
  tmp.forEach(i => {
    t.push( Math.floor( i * 0x15868 ).toString( base ).substring( 1 ) )
  });
  
  return t.join('');
}



// purely numeric using Base10
console.info( 'Numeric - Base 10: %s', uniqid(2, 10) );
console.info( 'Long Numeric - Base 10: %s', uniqid(4, 10) );

// Alphanumeric strings using Base16
console.info( 'Alphanumeric String - Base 16: %s', uniqid(2, 16) );
console.info( 'Long Alphanumeric String - Base 16: %s', uniqid(4, 16) );

Creating a random number for a local storage keyName

4 Answers4